The temperatures inside an operating gas turbine engine are extremely high, often at levels in excess of 450° C. When it is desirable to monitor the inside temperatures of components of the turbine, such as a turbine blade, or to monitor stresses placed upon such components during operation, a special sensing, amplifying and transmitting circuit is required. An effective solution to this problem is the use of wireless telemetry, such as that disclosed in published U.S. Patent Application Publication No US 2005/0198967 A1 entitled SMART COMPONENT FOR USE IN AN OPERATING ENVIRONMENT; or U.S. application Ser. No. 11/936,936 entitled INSTRUMENTED COMPONENT FOR COMBUSTION TURBINE ENGINE and U.S. application Ser. No. 11/521,193 entitled INSTRUMENTED COMPONENT FOR WIRELESS TELEMETRY.
In these above-cited patent applications, the general concept of using wireless telemetry is disclosed. The present patent application addresses specific problems encountered when implementing such technology.
Wireless telemetry circuit boards and components thereon that can withstand high temperatures can enable the extraction of data from stationary and moving components in high temperature environments, such as those experienced in internal combustion gas turbine engines. Electronic circuitry offer the possibility for real-time monitoring of component conditions during operation of turbine engines, such as industrial gas turbines, aircraft engines, and turbines used in the oil and gas industry. Knowing the condition of components in a turbine offers many benefits, including optimizing turbine operation based on internal engine parameters and enabling condition-based maintenance. Significant reductions in operation costs of advanced turbine engines may be realized by the use of monitoring devices. The current practice of instrumenting turbine components involves mounting sensors to components, running lead wires to routers and bringing large bundles of lead wires long distances out of the turbine to a monitoring location. The process is slow, labor intensive, expensive, and requires modification of many of the components of the turbine in order to allow for the inclusion of all of the lead wires.
In order to realize the advantage of extracting data from such a sensor system, it may be required to place the data transmitter on the coolest region of a hot component. This could result in the need for a wireless telemetry system that would function at temperatures exceeding 300° C., such as at the root of a blade in the flow path of a turbine engine. Current state of the art circuits using silicon or silicon-on-insulator (SOI) active components are not capable of operation at such high temperatures. Such a wireless telemetry circuit board would require a package, a board, runs, passive devices, active devices and connections capable of operating at temperatures exceeding 300° C.